The present invention relates to hoists and the like and more particularly to a hoist and method of adjusting same to enable relatively heavy loads to be raised with a minimum of input force.
U.S. Pat. No. 3,994,476 issued Nov. 30, 1976 to applicant describes and claims a hoist having a braking arrangement designed to be applied by a load supported on the line wound around the hoist windlass. The subject matter of such patent is hereby incorporated by reference. Lowering of the load, i.e., reverse rotation of the windlass, is achieved by applying torque to the windlass to rotate the same through the brake in the reverse direction. That is, the brake remains applied even when the windlass is rotated in the reverse direction. Thus, the operator is assured that the hoist will not allow the load to be dropped, even if the power mechanism causing reverse rotation of the windlass fails.
The hoist principles described and claimed in applicant's earlier patent readily lend themselves to incorporation into a hoist embodiment that is motor driven. Most motor driven hoists, though, include a relatively powerful motor incorporated directly therein. This makes such a hoist expensive, and significantly reduces the likelihood of it being used for many applications. It has long been recognized that it would be desirable to be able to drive a hoist with a low powered separable motor, such as is incorporated in a hand drill without a too large and complicated gear speed reduction unit. However, since the power of the hoist motor in most arrangements is used not only to raise a load, but also to provide braking during load lowering, it has not been practical to do so.